In a communication network it is desirable to provide conference arrangements whereby many customers can be bridged together on a conference call. In the so-called "dial-up" conference arrangements, each conferee is summoned at the appropriate time by establishing a communication path to the customer station. The customer is informed that he or she is wanted for a conference call and then added to the conference bridge where the customer can talk with the other conferees on the bridge.
When dial-up type conference arrangements are under the control of an operator, the operator's position can be furnished with supervisory equipment to permit the operator to monitor the status of each conference leg on the bridge in order to ascertain when a conferee answers, disconnects or is added to the bridge. Thus, the operator can inform the conferees on a conference when a party is to be added to or disconnected from the bridge.
If the conference is to be controlled from a customer station, it is generally not practical to provide each customer station with a supervisory capability similar to that of an operator's position.
Accordingly, without such supervisory capability, if a conferee inadvertently disconnects or the connection to the conferee's station is interrupted by an equipment failure, the absence of that conferee might go unnoticed by the remaining conferees.